SU1040611A1 - Device for monitoring amplification in uncaptured four-wire communications channels - Google Patents

Abstract

DEVICE FOR CONTROL OF AMPLIFICATION IN THE EMPLOYED FOUR-WIRE COMMUNICATION CHANNELS, containing at each intermediate station matching blocks, the outputs of which are connected to the inputs of the recording units of self-excitation signals, in which, in order to improve the reliability of the control by increasing the number of control thresholds, into it; at each intermediate station, a bandpass transmission filter unit, a bandpass reception filter unit and a decoder, the first and second inputs of which are connected to the outputs of the self-excitation signal recording units, inputs 5 of which are connected to the corresponding inputs of the reception bandpass filters whose inputs are connected to the outputs of the monitored the reception path, while the corresponding inputs of the bandpass filter block are connected to the inputs of the control: transmission path, and the outputs are connected to the inputs of the matching blocks , And on the other intermediate station I blky inputs of bandpass filters in the receiving outputs are connected to the controlled (the transmission path L, and outputs the transmission band of the filter unit are connected to the receiving path vhoyami controlled.

Description

about

9d The invention relates to the technique of epectrosibz and can be used in. Kotrol amplification equipment in the compaction instrumentation. A device for controlling amplification in unused four-wire low-frequency communication channels is known, which contains a control current generator, indicators and a key to which, forming loops at intermediate stations, with the help of measuring units, measure the gain in unallocated four-wire communication channels lL. However, the known device has. limited capabilities and low measurement accuracy. The closest technical solution to the present invention is a device for controlling amplification in unoccupied four-wire communication channels, containing, at each intermediate facility, matching blocks whose outputs are connected to the inputs of self-excited signal recording units. 2 However, this device has a low confidence controp. The purpose of the invention is to increase the reliability of the control by increasing the number of control thresholds. The goal is achieved by the fact that the gain control device in the unused four-wire communication channels, which contains matching blocks at each intermediate station, whose outputs are connected to the inputs of self-excitation signals recording blocks, introduces a band-pass transfer filter block, a block receive filters and a decyframer, the first and second inputs of which are connected to the outputs of the self-excited signal recording units, whose inputs are connected to the corresponding inputs of the block losovyh receiving filter having an input connected to the first tract kontroliruemog receiving outputs, the respective inputs of bandpass filters block transmitted. They are connected to the inputs of the controlled transmission path, and the outputs are connected to the inputs of the matching blocks, and at another intermediate station the inputs of the band-pass filter unit are connected to the outputs of the controlled transmission path, and the inputs of the T-loop band filter unit are controlled by the receive path. In the drawing, an electrical circuit of the proposed device is etched. A device for monitoring gain in indiscriminate four-wire communication channels contains, at each intermediate station, a block 1 of transmission bandpass filters, a block of 2 reception bandpass filters, a first 3 and a second 4 matching blocks, a first 5 JI second 6 blocks of registration of self-excited signals, the decoder 7, in addition to the drawing shows the monitored paths 8 and 9 receive and transmit, respectively. The device works as follows. . For definiteness, two auxiliary frequencies (e.g., two narrow frequency bands with average values of 32OO Hz and ZOO Hz) are distinguished in the monitored treatises of transmission and reception. In general, auxiliary bands can be allocated within the entire frequency range, i.e. from O, 3 kHz to 3.4 kHz. Separating the reference frequencies with respect to the fugue is selected from the conditions of the maximum permissible mutual influence and usually depends on the quality of the bandpass filter in blocks 1 and 2, the actual gain always determines the transmission coefficients in the control and transmission paths 9 and 8. Both educated test and test plumes work independently of each other. Each of them has its own condition of self-transport. Using two measuring plates, two (for a given device) threshold values of the gain values can be monitored. It is obvious that with the formation of a large number of control loops at the corresponding allocated auxiliary frequencies, it is possible to control a large number of threshold values of the gain values. In order to establish the actual (real) magnitude of the power in the monitored communication channel, it is necessary to decipher the state of the signals of the control self-excitation in all the formed loops. Thus, for example, when controlling gain with two threshold values (in accordance with the proposed device), it is possible to solve the problem of controlling the stability of the gain of the monitored channel by using two control loops, for example, during the operation of communication equipment. The permissible stability of the gain is determined under the condition that the actual value of the gain during operation is in the range between the lower and upper allowable values of the gain values. The output of the gain value beyond the allowable upper or lower limits is considered invalid and must be accompanied by the activation of an alarm (or, for example, by switching to the backup channel). Thus, to control the gain over two thresholds (upper and lower), the value of the measuring elements is chosen from the conditions of self-excitation at the minimum and maximum force for the corresponding control loop, i.e. for each pair of blocks 3 and 4 matching. Suppose, for example, that the stability of gain 15 in a channel needs to be controlled by. ± 2 dB. For this total attenuation of the first pair of matching blocks, the magnitude of the gain is chosen 2 dB less than real. the magnitude of the gain that exists in the communication channel at the time the communication equipment is put into operation. The value of the second pair of matching blocks is chosen 2 dB more than the actual amplification. communication. in the communication channel. With this choice; ; 25 dimming values and provided that the total gain in the channel is in the pre-. In the cases of its permissible values, in the nepii BOM control, the loop of total salary will be less than the total gain, and the condition caMCiw will remain in it. excitement. In the second loop at the same time. self-excitation will be absent, since the total gain will be less than the total attenuation of the measuring-elements. In this way, see, at normal., The nominal gain in the channel in the first loop will establish a self-excitation signal, which will be fixed by blocks 5 and 6 of the res., .-. the homing of the homing signals at their ends of the communication line at the same time. At the same time, the signal recording units are located. self-excitation produces at their outputs signals of the absence of self-excitation of geni in the second loop. thus, the inputs of both decoders 7 will receive 10, which corresponds to HOjb.

the maximum gain and alarm equipment is not: an alarm will be sent.

If the gain is reduced by more than 2 dB (beyond the limits of permissible values), the self-excitation signal will disappear in the first loop and the OO signal will be sent to the inputs of the decoders, i.e. In both loops, the self-excitation signal will be absent, which corresponds to the emergency state and an alarm signal will be sent to the input of the alarm equipment.

With an increase in the magnitude of the gain above 2 dB, self-excitation also occurs in the second loop. At the same time, at the inputs of the decoder, the signals 11 are in the vehicle, which also include an alarm. The appearance of the signal 01 on the inputs of the deshfrato signal should be accepted as a forbidden combination or as a signal of control equipment malfunction, since if the total attenuation in the first loop is smaller than in the second loop, then with an increase in the value of the gain causing self-excitation in the second loop In the first loop, self-excitation should be maintained. If self-excitation disappears in the first loop when increasing the gain, this can only indicate equipment malfunction, control (or an error when setting the initial value).

. Thus, the logical processing of the signals of the self-excitation state allows determining the general state of the accident and at the same time localizing the type of avarka (for example, what happened with the gain in the channel) ..

The proposed device allows simultaneous warning and alarm alarms that are triggered when the gain changes within a few thresholds.

Claims (1)

A gain control device for unoccupied four-wire communication channels, containing at each intermediate station matching blocks, the outputs of which are connected to the inputs of the self-excitation signal recording blocks, characterized in that, with a chain to increase the reliability of control by increasing the number of control thresholds, it will enter: on each intermediate station, a block of bandpass filters for transmitting, a block of bandpass filters for receiving and a decoder, the first and second inputs of which are connected to the outputs of the blocks for recording signals of self-pickup waiting, the inputs of which are connected to the corresponding inputs of the band pass filter unit, the inputs of which are connected to the outputs of the monitored reception path, while the corresponding inputs of the band pass filter block are connected to the inputs of the monitored transmission path, and the outputs are connected to the inputs of matching blocks, at another intermediate station | the inputs of the block of band-pass filters of reception are connected to the outputs of a controlled transmission path, and the outputs of the block of band-pass filters of transmission are connected to the inputs of a controlled The receive path. SU, 1040611